textproduct: Rapid City

KEY MESSAGES

- Severe weather expected this afternoon and evening, especially from the Black Hills to northwest South Dakota. Large hail, damaging winds, and isolated tornadoes possible.

- Severe storms possible across south-central South Dakota on Wednesday.

- Chance of severe weather with all hazards possible Thursday.

DISCUSSION

(This Afternoon Through Monday) Issued at 1109 AM MDT Tue Jun 2 2026

Upper level analysis has the forecast area in southwest flow with a low over southwestern Saskatchewan and a skinny ridge extending up through the Mississippi River Valley from High Pressure in the Southern Plains. At the surface, a cold front extends through eastern Montana into southeastern Wyoming. Radar imagery has thunderstorms already firing in the warm sector east of the boundary.

For this afternoon and evening, the cold front will provide the primary focus for thunderstorm development. As this front moves slowly east, development will likely occur over the Black Hills and most of western South Dakota, especially across northwestern South Dakota. Model soundings show steep lapse rates, deep layer sheer and MLCAPE around 2500 J/kg. These ingredients suggest the potential for supercell storms capable of producing large hail, severe winds, and even a tornadic storm. Additionally, the presence of a low level jet this evening should result in storms continuing through late evening and possibility into the early morning hours.

The cold front will move slowly east on Wednesday as the upper low slowly shifts into southeastern Saskatchewan and western Manitoba. Models indicate a secondary surface low will spin up over central South Dakota with a trailing cold front into western Nebraska panhandle. This boundary will once again be the focus for convective initiation during the afternoon and evening hours. Again, these storms will have the potential for large hail and strong wind gusts. Forecast soundings indicate steep lapse rates, MLCAPE around 2500 J/kg over central South Dakota, and shear up to 35-40kts over south central South Dakota, though shear is forecast to be much higher across north central South Dakota.

Thursday will be another big day for severe storms across the forecast area as the upper low slides through Manitoba and a shortwave crosses the Rockies into the forecast area by Friday afternoon and evening. At the surface, a low will spin up over southeastern Montana and slide into west-central Nebraska. This boundary will be the focus for severe storms on Thursday with diurnally enhanced development. The environment looks like a typical northern Black Hills supercell environment capable of very large hail. Additionally, storms may end up growing into an easterly propagating MCS overnight, resulting in a severe wind threat for south-central South Dakota by late evening.

On Friday, could have some lingering showers in the morning, as the cold front drops southward and a wave clips northwestern South Dakota. Also, some diurnally driven showers are possible over the Black Hills in the afternoon.

Saturday appears to be mainly dry as a weak shortwave ridge slides through the area, with chances for storms returning Sunday through early next week.

Temperatures through the period will gradually warm through this weekend, with highs running about 10 degrees above average and lows about 5 degrees above average.

AVIATION

(For the 12Z TAFS Through 12Z Wednesday Morning) Issued At 537 AM MDT Tue Jun 2 2026

A few lingering showers/storms will be this morning but the main impacts to aviation weather will happen in the afternoon and evening.

While VFR conditions are mainly expected through the TAF period, another round of strong to severe thunderstorms is likely this afternoon into evening. MVFR/IFR conditions are possible within the storms.

After the storms, the wind will shift to the west/northwest tonight.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.